DevDay Community Hackathon: Berlin

A one-day community hackathon built around OpenAI's Codex and ChatGPT, running 10:00 to 18:00 across three tracks. Developer entries are judged on technical merit and the demo, GTM and Sales entries on the strategy, and Founder entries on a feature that solves a real problem. There is a standard track for anyone who does not fit one of the three. Hosted by Max Jendrall, a Berlin-based OpenAI Codex Ambassador, with Pauline P. Narvas, under Codex Community Events. Free, but registration is approval-gated and the exact address goes only to people who are accepted. Track leads are confirmed shortly before the day, and entrants can win a ticket to the official DevDay Exchange on 26 October. Why go: a build day with judging attached rather than another talk about agents. Best for developers and founders who want to ship something with Codex in a room of people doing the same.